Chemistry Review

Chemistry

● Chemistry is the study of matter● WHMIS - Workplace Hazardous Material

Information System● Know the 8 symbols

Particle Model of Matter● Matter is classified into solids, liquids and gases based

on particle distance and bonding● Matter can be further classified into pure substances

and mixtures● Elements and compounds are both pure substances

Mixtures● Mixtures can be heterogenous (mechanical mixtures) or

homogenous (solutions)● Heterogenous includes ordinary mechanical mixtures,

colloids (and emulsions), and suspensions

Changes● Chemical reactions must create a new substance● If a new substance is not created then the matter went

through a physical change

2 Laws

● Law of Conservation of Matter states that in a chemical reaction all mass is preserved - mass of reactants = mass of products

● Law of Definite Composition states that compounds are always put together in a specific way - Water is ALWAYS H2O

Pure Substances● Compounds are made of at least 2 different elements● Elements can bond with themselves to create diatomic

molecules● Molecules are at least 1 element bonded to another

element

Atoms● Atoms are made up of protons(+), electrons (-), and

neutrons● Protons and neutrons are found in the nucleus - very

heavy● Electrons are found outside the nucleus - very light

Periodic Table● Elements are arranged on the periodic table according

to their number of protons● The table is split into metal, metalloids, and non metals● Atomic number, symbol, atomic mass

Chemical Families● Alkali metals - very reactive, first column, one extra

electron● Alkaline Earth Metals - reactive, 2nd column, two extra

electrons● Halogens - very reactive, 2nd last column, short 1

electron● Noble gases - inert, last column, full electron shell

Compounds● Metals and non metals may bond together, transferring

electrons to create ionic compounds● Non metals and non metals may bond, sharing

electrons to create molecular compounds

Naming compounds● Ionic - Metal first then non metal with -ide ending● Molecular - first non metal has numerical prefix (but

never mono), second non metal has numerical prefix and -ide ending

Chemical Reactions

● Catalysts speed up chemical reactions but are not used in the reaction

● Inhibitors slow down chemical reactions but are not used in the reaction

● Rust is formed through oxidation● Combustion is the burning of carbon

molecules in the presence of oxygen● Electroplating can slow down rusting